In modern electronic systems, it is sometimes necessary to connect a pair of printed circuit boards in edge to edge alignment. One board is provided with a male connector for coupling with a corresponding female connector of the other board. Thus, the two boards are aligned each to the other in the same plane and connected together at a first edge. The connectors coupling together the two boards are typically of standard type, are located at such first edge and have an inserting direction perpendicular to the edge direction and parallel to the plane of the boards. One of the printed circuit boards may be, for example, an adapting board serving to couple the other printed circuit board to, again by way of example, a back panel. The connector for connection to the back panel is located at a second edge of the adapting board, opposite and parallel to the first one, and the inserting direction of this connector, for coupling to the back panel, is identical to the previous one.
It is known that, due to the friction and contact pressure exerted by electrical contacts, the insertion and disconnection operations involve a force acting on the connectors. Therefore, if a board pair of the exemplary type (that is, consisting of a printed circuit board coupled to a printed circuit adapting board) is pulled out of its housing, a pull has to be exerted on the first board to pull it out. Hence, there is the risk that the adapting board will remain inserted in the housing and disconnect itself from the first board while remaining connected to the back panel. Thereafter, the removal of the adapting board, for maintenance, testing or repairing, is difficult, if not impossible.
The present invention overcomes this problem and provides a locking device for printed circuit board connectors which is simple, inexpensive and reliable. Moreover this device may be used with standard connectors, in standard environment for such connectors, which standard is very restrictive in terms of encumbrance and space available among contiguous connectors. The locking device of the invention is further of advantage because it directly acts on the connectors, without interference with other elements and without imposing constraints additional to those imposed by the standards in the use of printed circuit boards and in the allocation thereon of electronic components.